#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 10;
int s, p;
struct point{
    int x,y;
}po[505];
int f[1005];

int dis(point a,point b){
    return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y)*(a.y - b.y));
}

bool check(int d){
    for(int i = 1; i <= s;i++){
        
    }

}


void merge(){
    
}

int main()
{
    cin >> s >> p;
    for(int i =1; i<= s; i++)f[i] = i;
    for(int i = 1; i<= p; i++){
        int x , y;
        cin >> x >> y;
         po[i].x = x*100;
         po[i].y = y *100;
    }

    int ans = 0;
    int l = 0, r = 2000000;
    while(l < r){
        double mid = l + r >> 1;
        if(check(mid))ans  = mid,r = mid;
        else l = mid + 1;
    }
    printf("%.2lf",((double)ans)/ 100);

   return 0;
}
